The Wrong Guys

Magic

Arcane magic is forbidden. It tends to drive its wielders mad, and so the witch hunters (paladins) of Aldaran are tasked with destroying anyone who uses arcane magic.

Druidic magic is considered to be a separate thing from divine magic. While outwardly similar in form, it does not rely on a divine figure as intermediary, with power being drawn instead directly from nature. For these reasons, it is considered highly unnatural and is just as banned as arcane. The fact that its wielders can do things like turn into bears and summon bears while throwing lightning might also help.

Divine magic is granted by a god to mortals, and is considered both legal and safe to use. However, some of the common folk mistrust it almost as much as arcane magic.

Rumours of dubious relevance:

Some of the more…pervasive myths shared by overeager paladins in training.

The high priests can call upon devas to aid them in battle with nothing but a word.

Certain mortals, blessed by the gods, can channel enough raw divine power to rival angels.

An archon serves within the ranks of the order, under the guise of one of the following, depending largely on who did something cool recently:
Halibran Fomörrek, a dwarf paladin, who’s currently part of the Triumvirate, though she’s thinking about stepping down, Kasael Caithes, a human adept who is also rumored to be one of those mortals capable of defeating angels with divine magic, and quite possibly healed Audric once (he doesn’t entirely remember that, on account of being near death at the time). Damian Gwyngam, a high ranking human paladin from Rysal, who is fighting on the north border, or Medric Brightblade, halfling paladin who’s more or less in charge of the hills area, because messengers only show up every 5 weeks-ish, at best.

Fey are fiends in different guises, rather than the two being separate, but equally malevolent beings.

Sorcerers do not worry about the destruction of their souls because they have no soul to begin with. They are born with arcana in their hearts where a soul should be, and this is why they can channel it.

The last two are actually known to be believed by some of the higher-ranking members of the Order. They tend to be amused when the rest of the rumors come around.